CN212588513U

CN212588513U - MEMS microphone

Info

Publication number: CN212588513U
Application number: CN202020961621.7U
Authority: CN
Inventors: 柏杨
Original assignee: Ruisheng Technology Nanjing Co Ltd
Current assignee: Ruisheng Technology Nanjing Co Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2021-02-23
Anticipated expiration: 2030-05-29
Also published as: WO2021237800A1

Abstract

The utility model discloses a MEMS microphone, through with encapsulating casing snap-on the flexible substrate in order to form accommodating space, in the accommodating space that encapsulating casing and flexible substrate formed, MEMS chip and ASIC chip are fixed respectively on the flexible substrate to the electric connection of MEMS chip, ASIC chip and flexible substrate has been realized, the flexible substrate sets up and encircles at least MEMS chip be located buffer in the accommodating space. The flexible connection formed by the buffer part can release part of external kinetic energy, and the volume of the accommodating space is enlarged to slow down the rising speed of the air pressure of the accommodating space, so that the impact on the vibrating diaphragm, the back plate and other structures arranged in the MEMS chip is reduced, and the reliability of the MEMS chip in extreme environments such as atmospheric flow, falling, vibration and the like is improved.

Description

MEMS microphone

[ technical field ] A method for producing a semiconductor device

The utility model relates to a miniature microphone field especially relates to a MEMS microphone.

[ background of the invention ]

The existing MEMS microphone is generally formed by packaging an MEMS chip, an ASIC chip, a packaging substrate and a shell. The MEMS chip and the ASIC chip are attached to one side of the packaging substrate, and one side of the packaging substrate, which is wrapped by the shell, is connected with the MEMS chip and the ASIC chip in a lead bonding or TSV (through Silicon Via) through hole mode. In an actual use terminal of an MEMS microphone such as a mobile phone and a flat panel, the other side of the package substrate is electrically connected to a Flexible Printed Circuit (FPC) through an external pad. The packaging substrate is internally provided with a multilayer structure comprising a metal layer and an insulating layer, occupies a larger height space, and is not beneficial to realizing the lightness and thinness of the MEMS microphone.

In general, an external pad of a package substrate is fixed on one side of the package substrate, and the position is not flexible enough, which brings certain limitation to connection and matching of a microphone and other hardware in a later stage.

In addition, since the MEMS chip and the hard package substrate are usually bonded by glue, which belongs to rigid connection, external kinetic energy is concentrated on a movable part of the MEMS chip, such as a diaphragm, and released in extreme environments of atmospheric flow, dropping, vibration, and the like, so that the diaphragm or the backplate is easily broken, and even the MEMS chip fails.

Therefore, there is a need to provide a new technical solution to solve the above-mentioned drawbacks.

[ Utility model ] content

An object of the utility model is to provide a MEMS microphone.

In order to achieve the above object, the utility model provides a MEMS microphone, its including the encapsulation casing, with the encapsulation casing encloses into accommodating space's flexible substrate, accept in the accommodating space and install in MEMS chip and ASIC chip on the flexible substrate, the MEMS chip with ASIC chip and flexible substrate electric connection, the flexible substrate sets up and encircles at least MEMS chip be located buffer in the accommodating space.

Preferably, the buffer portion has a hardness smaller than that of the flexible substrate.

Preferably, the thickness of the buffer portion is smaller than that of the flexible substrate.

Preferably, the buffer part has a corrugated structure.

Preferably, the buffer portion surrounds the MEMS chip and the ASIC chip.

Preferably, the MEMS chip is electrically connected to the ASIC chip through a first lead, and the ASIC chip is electrically connected to the flexible substrate through a second lead.

Preferably, the MEMS chip is provided with a first electrical through hole and a first contact point located at a bottom end of the first electrical through hole, the ASIC chip is provided with a second electrical through hole and a second contact point located at a bottom end of the second electrical through hole, and the flexible substrate is provided with an inner pin electrically connected to the first contact point of the MEMS chip and the second contact point of the ASIC chip.

Preferably, the flexible packaging substrate is provided with an outer pin, and the MEMS chip and the ASIC chip are electrically connected to the outer pin of the flexible substrate.

Preferably, a glue protection area is arranged on the periphery of the MEMS chip or the ASIC chip and used for sealing the connection position of the MEMS chip or the ASIC chip and the flexible substrate.

Preferably, the flexible substrate is a flexible circuit board.

The beneficial effects of the utility model reside in that: the packaging shell is directly fixed on the flexible substrate to form an accommodating space, the MEMS chip and the ASIC chip are respectively fixed on the flexible substrate in the accommodating space formed by the packaging shell and the flexible substrate, the MEMS chip, the ASIC chip and the flexible substrate are electrically connected, and the flexible substrate is provided with a buffer part which at least surrounds the MEMS chip and is positioned in the accommodating space. The flexible connection formed by the buffer part can release part of external kinetic energy, and the volume of the accommodating space is enlarged to slow down the rising speed of the air pressure of the accommodating space, so that the impact on the vibrating diaphragm, the back plate and other structures arranged in the MEMS chip is reduced, and the reliability of the MEMS chip in extreme environments such as atmospheric flow, falling, vibration and the like is improved.

[ description of the drawings ]

Fig. 1 is a schematic structural diagram of a MEMS microphone according to a first embodiment of the present invention;

fig. 2 is a schematic structural diagram of a MEMS microphone according to a second embodiment of the present invention;

fig. 3 is a schematic structural view of the flexible substrate provided with the buffer portion in the MEMS microphone of the present invention;

fig. 4 is a schematic view illustrating a state in which the buffer portion of fig. 3 is opened.

[ detailed description ] embodiments

The present invention will be further described with reference to the accompanying drawings and embodiments.

It should be noted that all the directional indicators (such as upper, lower, left, right, front, back, inner, outer, top, bottom … …) in the embodiments of the present invention are only used to explain the relative position between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

It will also be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Referring to fig. 1 to 2, the present invention provides a MEMS microphone 100, which includes a package housing 10, a flexible substrate 20 enclosing a receiving space 50 with the package housing 10, a MEMS chip 30 and an ASIC chip 40 received in the receiving space 50 and mounted on the flexible substrate 20, wherein the MEMS chip 30 and the ASIC chip 40 are electrically connected to the flexible substrate 20, and the flexible substrate 20 is provided with a buffer portion 24 surrounding at least the MEMS chip 30 and located in the receiving space 50. The MEMS chip 30 is configured to receive the sound wave entering the receiving space 50, convert the sound wave into an electrical signal, transmit the generated electrical signal to the ASIC chip 40, and output the electrical signal to an external circuit through the ASIC chip 40, so as to convert the sound into the electrical signal.

Specifically, the package housing 10 is made of a metal material and has a function of shielding electromagnetic interference, and the package housing 10 is fixed on the flexible substrate 20 by bonding or welding. The packaging shell 10 or the flexible substrate 20 is provided with a sound inlet 21, and the sound inlet 21 is used for transmitting sound waves into the accommodating space 50. In this embodiment, the sound inlet 21 is disposed on the flexible substrate 20 and below the MEMS chip 30.

Referring to fig. 1 again, in a preferred embodiment, the MEMS chip 30 and the ASIC chip 40 are electrically connected through a first lead 31, the ASIC chip 40 and the flexible substrate 20 are electrically connected through a second lead 41, and the flexible substrate 20 is provided with an inner pin 22 connected with the ASIC chip 40 through the second lead 41.

Referring to fig. 2 again, in another preferred embodiment, the MEMS chip 30 has a first electrical through hole 32 and a first contact point 33 located at the bottom end of the first electrical through hole 32, the ASIC chip 40 has a second electrical through hole 42 and a second contact point 43 located at the bottom end of the second electrical through hole 42, the flexible substrate 20 has an inner lead 22 for electrically connecting the first contact point 33 of the MEMS chip 30 and the second contact point 43 of the ASIC chip 40, and the first contact point 33 and the second contact point 43 are protrusions protruding beyond the surface of the MEMS chip 30.

The process steps involved in figure 2 will now be described in detail:

step S1, forming an electrical through hole on the MEMS chip and the ASIC chip by using a TSV (through Silicon Via) process, and reserving a contact point at a position corresponding to the electrical through hole at the bottom of the chip;

step S2, carrying out intermetallic bonding between the inner pin on the flexible substrate and the contact point at the bottom of the electric through hole on the MEMS chip or the ASIC chip through solder;

s3, dispensing and curing glue to form a glue protection area on the periphery of the MEMS chip or the ASIC chip, wherein the glue protection area is used for sealing the connection part of the MEMS chip or the ASIC chip and the flexible substrate;

and step S4, dispensing solder paste on the joint of the flexible substrate and the package shell, attaching the package shell to the corresponding position of the flexible substrate, and then performing reflow soldering to fix the package shell.

Preferably, the flexible substrate 20 is a flexible circuit board.

Further, on the basis of the two embodiments of fig. 1 and fig. 2, the flexible substrate 20 is further provided with an outer pin 23, and the MEMS chip 30 and the ASIC chip 40 are electrically connected to the outer pin 23 of the flexible substrate 20 through an inner pin 22. The utility model discloses in, length, position, the direction that sets up at the outer pin 23 of flexible substrate 20 can set up according to actual demand wantonly to realize in being connected of MEMS microphone and outside hardware in a flexible way.

In the embodiment of fig. 1 and 2, the receiving space is formed by directly fixing the package housing on the flexible substrate. In an accommodating space formed by the packaging shell and the flexible substrate, the MEMS chip and the ASIC chip are respectively fixed on the flexible substrate, and the electrical connection of the MEMS chip, the ASIC chip and the flexible substrate is realized. The packaging structure saves the space of the hard packaging substrate, reduces the height of a product, and saves the steps and cost of the packaging process.

Referring to fig. 1, in an embodiment, the buffer portion 24 is disposed around the MEMS chip 30; referring to fig. 2, in another embodiment, the buffer 24 is disposed around the MEMS chip 30 and the ASIC chip 40. The buffer portion 24 is a corrugated structure and is located in the accommodating space 50. In one embodiment, the hardness of the buffer portion 24 is less than the hardness of the flexible substrate 20; in another embodiment, the thickness of the buffer portion 24 is smaller than the thickness of the flexible substrate 20; of course, a combination of the two cases may be used. In a normal usage environment, the buffer portion 24 is not opened, and as shown in fig. 3, the flexible substrate 20 is not deformed significantly. Under extreme environments such as atmospheric flow, fall, vibration, buffer portion 24 can be opened in the twinkling of an eye, as shown in fig. 4, and flexible connection can release partial outside kinetic energy, in addition, can also enlarge accommodating space 50's volume, slows down the speed that accommodating space 50 atmospheric pressure rises to reduce the impact to structures such as vibrating diaphragm and backplate that set up in MEMS chip 30, improved reliability level under extreme environments such as atmospheric flow, fall, vibration of MEMS chip 30.

The utility model discloses a with the packaging shell snap-on in order to form accommodating space on the flexible substrate, in the accommodating space that packaging shell and flexible substrate formed, MEMS chip and ASIC chip are fixed respectively on the flexible substrate to MEMS chip, ASIC chip and flexible substrate's electric connection has been realized, the flexible substrate sets up and encircles at least MEMS chip is located buffer in the accommodating space. The flexible connection formed by the buffer part can release part of external kinetic energy, and the volume of the accommodating space is enlarged to slow down the rising speed of the air pressure of the accommodating space, so that the impact on the vibrating diaphragm, the back plate and other structures arranged in the MEMS chip is reduced, and the reliability of the MEMS chip in extreme environments such as atmospheric flow, falling, vibration and the like is improved.

The above embodiments of the present invention are only described, and it should be noted that, for those skilled in the art, modifications can be made without departing from the inventive concept, but these all fall into the protection scope of the present invention.

Claims

1. The MEMS microphone comprises a packaging shell, a flexible substrate, an MEMS chip and an ASIC chip, wherein the flexible substrate and the packaging shell form a containing space in a surrounding mode, the MEMS chip and the ASIC chip are contained in the containing space and are installed on the flexible substrate, the MEMS chip and the ASIC chip are electrically connected with the flexible substrate, and the MEMS microphone is characterized in that the flexible substrate is provided with a buffering portion which at least surrounds the MEMS chip and is located in the containing space.

2. The MEMS microphone of claim 1, wherein a hardness of the buffer is less than a hardness of the flexible substrate.

3. The MEMS microphone of claim 1 or 2, wherein a thickness of the buffer portion is smaller than a thickness of the flexible substrate.

4. The MEMS microphone of claim 1, wherein the buffer is a corrugated structure.

5. The MEMS microphone of claim 4, wherein the buffer surrounds the MEMS chip and the ASIC chip.

6. The MEMS microphone of claim 5, wherein the MEMS chip is electrically connected to the ASIC chip by a first lead, and the ASIC chip is electrically connected to the flexible substrate by a second lead.

7. The MEMS microphone as claimed in claim 5, wherein the MEMS chip is provided with a first electrical through hole and a first contact point at a bottom end of the first electrical through hole, the ASIC chip is provided with a second electrical through hole and a second contact point at a bottom end of the second electrical through hole, and the flexible substrate is provided with an inner pin to electrically connect the first contact point of the MEMS chip and the second contact point of the ASIC chip.

8. The MEMS microphone of claim 6 or 7, wherein the flexible substrate is provided with an outer pin, and the MEMS chip and the ASIC chip are electrically connected with the outer pin of the flexible substrate.

9. The MEMS microphone of claim 1, wherein the MEMS chip or the ASIC chip is provided with a glue protection area on the periphery thereof, and the glue protection area is used for sealing the connection between the MEMS chip or the ASIC chip and the flexible substrate.

10. The MEMS microphone of claim 1, wherein the flexible substrate is a flexible circuit board.